Natural Selection Amplify Critical Juncture

Northern foxes can have different fur colors. The foxes hunt squirrels for food. Foxes that have fur the same color as their environment are better at getting close to squirrels and catching them. The diagrams below show three possible fox populations. If their environment changes to have only brown dirt, which of the following fox populations will most likely survive?

• Populations 1 and 2 will most likely survive.

• Populations 2 and 3 will most likely survive.

• Only Population 2 will survive because it is the only population with variation.

• All the populations will survive because the foxes will change the color of their fur if they need to.

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NGSS.MS-LS4-4

A new trait will only become more common in a population if it is _______________________________

• harmful to predators

• adaptive

• recessive

• dominant

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NGSS.MS-LS4-4

What changed in the environment to cause evolution?

• The water temperature increased.

• The water temperature decreased.

• The water temperature did not change.

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NGSS.MS-LS2-4

NGSS.MS-LS4-1

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What change in the environment caused the evolution? 岩石越小，越适合斑点小的鱼生存。

• The amount of large riverbed rocks increased.

• The amount of small riverbed rocks increased.

• The amount of riverbed rocks did not change.

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NGSS.MS-LS2-4

NGSS.MS-LS4-4

How did the cactuses (仙人掌) evolve from 1970 to 2015?

• Medium spine size became an adaptive trait.

• Medium spine size became a non-adaptive trait.

• Small and large spine sizes became adaptive traits.

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NGSS.MS-LS4-4

What change in the environment caused the evolution?

• The tree bark became gray.

• The tree bark became black.

• The tree bark became black and gray.

• The tree bark became white.

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NGSS.MS-LS2-4

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Why did the population evolve from medium to thick?

• Medium is the adaptive trait.

• Thick is the non-adaptive trait.

• The environment became more cold.

• The environment became more hot.

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NGSS.MS-LS2-4

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Which of the following best describes the concept of natural selection?

• A process where organisms better adapted to their environment tend to survive and produce more offspring

• A random change in the DNA sequence of an organism

• The movement of individuals from one population to another

• The intentional breeding of organisms to produce desired traits

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NGSS.MS-LS4-4

In an experiment to study natural selection, a population of beetles is observed over several generations. Initially, the population is 50% green and 50% brown. After several generations, the population is 80% brown. What is the most likely explanation for this change?

• Green beetles are more attractive to predators

• Brown beetles have a higher mutation rate

• Green beetles reproduce more slowly

• Brown beetles are less visible to predators

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NGSS.MS-LS2-4

NGSS.MS-LS4-4

Which of the following is a critical juncture in the process of natural selection?

• The initial mutation that introduces a new trait

• The point at which a trait becomes advantageous

• The extinction of a competing species

• The migration of a species to a new habitat

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NGSS.MS-LS4-4